Ncert Exercises & Solutions

Identify the species having the same bond order:

a. N₂
b. N₂⁻
c. F₂⁺
d. O₂⁻

1. (a), (b)
2. (b), (c)
3. (c), (d)
4. (a), (d)

N₂
Bond order = 3
N₂⁻
One electron is added to an antibonding orbital.
Bond order = 3 − 0.5 = 2.5
F₂⁺
F₂ has bond order = 1. Removal of one electron from a π* antibonding orbital increases bond order by 0.5.
Bond order = 1.5
O₂⁻
O₂ has bond order = 2. Addition of one electron to a π* antibonding orbital decreases bond order by 0.5.
Bond order = 1.5

Therefore:

N₂ = 3
N₂⁻ = 2.5
F₂⁺ = 1.5
O₂⁻ = 1.5

Hence, F₂⁺ and O₂⁻ have the same bond order.